Railway-traffic-controlling apparatus



R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPARATUS Nov. 22, 1927.

2 Sheets-Sheet 1 INVENTORI a l a W CM BY A a ATTORNEY Filed Aug. 24, 1923 'R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPARATUS Nov. 22, 1927.

Filed Aug. 24, 1923 2 Sheets-Sheet 2 Patented Nov. 22, 1927.

nairan sr irss PATENT oFFrcEQ-i RONALD A. MCCANN, on swissvannl, rnri'NsYLvAnrA," As'sIGNoR TO THE UNION 1 on PENNSYLVAN svnnn, rmqnsYLvANIA, ,A CORPORATION J nArLwAY-rnAFrro-oonrROLLING Arm res Application filed. August 24, 1923'. Serial. ri ped 1,102.

or other authorized oilicial. 'M'ore particu= larly my invention relates to the raclrway,

portion of such apparatus.

I will describe one form ant arrangement of apparatus,embodying my invent on, and

, will'then point out the novel features thereof in claims. I

In the accompanying drawings, F ,1

and 1, when placed end to end with 1- to the left, form a diagrammatic view showing one form apparatus embodying my invention.

Similar reference characters refer, to similar parts in both figures of this draw -v ing. 7

Referring to this drawing, the reference characters land 1" designate the track rails of a single track railway over which trailic normally moves in both directions. The stretch of track shown in the drawing is provided with two passing tidings F and F, respectively, located at the left hand end and right hand end of the stretch. Only the right hand half of siding F is shown in the drawing but it is understood that the apparatus associated with the two sidings F and F? is identical. The track rails 1 and l are divided, by'means of insulated joints 2-2, into a plurality of successive track sections A B, B-C, C-D, DJE, EQ etc, it being obvious that any ason able number of such sections may occur between two consecutive passing sidings, de pending upon the actual conditions.

Trafiic from right to left over the stretch oi track shown in the drawing is controlled by signals S and S located adjacent points Q and A, respectively. lR'illC iroin leiit to right over this stretch is governed by a signal S locatedadjacent point E andanother similar signal not shown in the drawing but located adjacent the left hand end of siding F.

As shown in the drawing each of the signals S S and S is a color light signal and is provided with three SI 'HEIl lQIHPS l, 5 and adapted, when lighted, to pro ectance 7 though this particular form'of signal is not a beam of red light, ofyellow light or green light, respectively, and thus display a stop, a caution or a proceed indication in accordwith standard signaling practice,

essential to the presentinvention. Y 1

Each endlot each section is provided with a source or track circuit such as a. secondary t of a track transformer designated "in general by the reference character T'and each or which transformers is specifically designated by an exponential character.

Each such secondary? .is constantly con nected across the rails of the-associated section one ad acent each end thereof, and the primary 8 of each transformer T is" at.

times supplied with alternating current as will appear hereinafter. interposed between one rail' 1 and the secondary 7 ofea'ch tracktransformer TV is an impedance 9, one i nating current.- For example, relay R is provided with a circuit which passesltroin the secondary of line transformer Ii,

through wire 21,winding 20 of relayR and wires 22, 23 and 24: bacl; totransitormer H Aline transiornier designated by the corresponding Fto the location is provided for each section. The primary of each such transformer H constantly supplied with alternating current from an lternator O The winding 15 reference character H with an exponent 7 7 "Associated with each track relay Ric a.

' back to transformer H line-relay designated by the reference character W with an exponent corresponding to the location. Referring particularly to line relay this relay is provided with a cir ,cuit which passes from the secondary of transformer M whose primary is constantly. supplied with alternating current from transformer H through wire 25, front contact 26' of line relay W wire 27, front contact 30 of track relay R wire 31, back contact 32 of a stick relay 1 wire'38, front contact 34 of track relay R wire 35, winding of relay W andwires 36, 37 and 38 back to transformer M This circuit is provided with a branch whichpasses from wires and 29, through front contact 28 of stick relay K and back towire 27. It is therefore evident that relay i isen'ergized only when relays VW, R and are encrgized and relay K is de-energized, but that when relay K is energized, the closing of its front contact 28 removes relay W from the control of relay N Line relays 'W', WV and VV are provided with circuits ere actly like those just traced for relay VJ.

Line relay W is provided with a circuit which passes from the secondary of line transformer H through wires 39 and 40, back contact ll of relay 1 wire 4-2, front contact. 1-3 of track relay R wire 44c, back contact 45 of relay G wire 46,

front contact L7 of track relay R wire 4L8, front contact 49 of track relay R", wire 50, back contact 51 of relay K wire 51 front contact 52 of track relay R, wire 53, winding of relay W and wires 54, (30, and 55 It .follows that relay is engerized only'wlien relays R R R and R are energizedand relays I, G and K are de-energized. An auxiliary circuit is also provided for relay V which passesfrom transformer H through wires .56 and 57, front contact 58 of stick relay K wire 59 back to wire 48, thence as before to wires 5e and 60 back to transformer if. It will therefore be clear that when stick relay K is energized, as by a train moving from left to right into section E F at point E, the closing of front contact 58 on relay K removes relays R R G and I from the control of relay W Relay at point B is provided with circuits similar to those just traced. for relay W", the control for relay W extending. beyond the limits ofthe drawing.

Relays N and W U associated with siding F and line relay associated with. siding F are all of the polarized, three-position type. Each of these relays is provided with two windings l6 and 17 the latter. of which is constantly connected with a source of energy. Thus, referring particularly to relay W a'ci'rcuit is provided, passing from transformer H through Wires 89 and 61, winding 17 of line relay W and wire t2,

one?

relay is therefore responsive to reversals of the relative polarity of the current supplied to winding 16. One path for this current is from left hand terminal of the" secondary of transformer M through .Vvllfi 64-, front contact 65 of line relay l1 Q wire 67-8, front contact 67 of line relayVi wire '68,.back contact 69 of stick relay l wire 70, front contact 71 oftrack relay R", wire f72, back contact 73 of relay 1*, 7 5 of track relay R wire-'76, front contact .7? of track relay R wire 178, back contact 7 9 of relay G wire 80, back contact .81 of relay K wire 82, front contact 83 of track relay 1 ,'wire 84, winding 16 0f line relay W wires 62, 63, 55, 60, 60, 5-1 and 85, front wire 7 1, front contact contact 86 of line relay VVF' and wire 8? back to transformer M .Thefpriinary"of transformer M is constantlysupplied Wlllll' alternating current from transformer H; It is clear that this clrcult can be closed only when relays VJ,,R R R and R are energized and relays K 1*, G and K are de- 7' energized, under which conditions the current supplied to relay Vi is of what I shall term normal relative polarity, and the contact fingers of this relay are swung to ward the right. When relay i V is de-energized, however, as by a train moving from right to left in section CD, relay K, as

will appear hereinafter, is energized the circuitfor relay Vi now passes from the right hand terminal of the secondary of transformer M through wire 87, back contact 65 of line relay Vi wire 88, front contact 69 of stick relay K, wire 70, thenceas before to wire then over back contact 36 of line relay V97 and wire 64 back to transformer M lVhen this circuit is closed re lay W is supplied with current ofwhat I 7 shall term reverse relative polarity"? and the contact fingers thereof are swung tor-wind the left. If for any reason the energizing circuits for this relay are-interrupted the supply of current to. winding 16. of relay 4V:

is discontinued and the contact fingers there-v of assume an intermediate position. It will therefore be clear that armatures 65 and 86 wire 93, winding of relay G and wires 63 and 55 back to transformer H lit is plain that this circuit is closed only when relay 1 is energ zed and relay VF is ener A stick provided with a pickup circuit whichpasscs from transform-er H through wires 95. and

96, back contact 97 of line relay W wire 98, back contact 99 of track relay R, wire 100, back contact 101 of track relay R, wire 102, front contact 103 of relay V wire 10 1, winding of relay vK, and wires 105, 23 and 107 back to transformer H This circuit is closed only when relays R, R and Vi are de-energized and relay V7 is energized. circuit is also provided which passes from transformer H through wires 95 and 110, back contact 111 of track relay R, wire 112, front'contact 109 of relay K wire 108, and wires 105, 23 and 107 to transformer H It will thus be plain that if a train moves from left to right through section CD relay W will be de-energized'and that relay K will therefore not pick up; but thatif a train moves fromright toleft relays R and V will be de-energized and entrance of the train into section CD atpoint D will deenergize relays R and W but relay W is a' slow-releasing relay and stick relay K therefore has time enough to close its front contacts before the front contacts of relay N ars openedfollowing the de-energization of that relay. .Stick relay K is thenheld in its energized positionover its own front contact as long as track relay R is deeenergized by a'train occupying any portion of section C-D. v

, The control of each stick relay K K K K and K is analogous to the control of stick relay K. The remaining stick relays K K and K are controlled in part by the associated repeater relays G. Referring particularly to relay K its pick-up circuit.

starts with transformer H and passes through wires 39 and 113, back contact 114- of track relay R wire 115, front contact 116 of relay G wire 117, winding of relay K and wires 118, 63 and back to transformer H It will be plain. that this circuit is closed only .when relay 9 R is de-energized and relay G is energized.

similar to that d-escribedfor relay K v It will be observed that certain of the stick relays K are provided with repeater relays designated by. the reference character P and having an exponent corresponding to the location. F or example, relay isincluded The retaining, .or stick circuit for the relay K passes from in a circuit passing from transformer H through wires 21 and 121, front contact 122 of stick relay K wire 123, back contact 12 1 of track relay R wire 125,back contact 126 of stick'relay K wire 127, back contact 128 of track relay L6, wire 129, winding of relay P and wires 130,23 and 24 back to "transformer H It follows thatrelay P normally repeats the condition of relay K but,

that the circuit passes over a back contact 125 oftlie. opposing stick relay K, thus checking the-position of that relayJ The control of relay P? is precisely; similar to that of relay Pf.

- Relay-P is controlled by a circuit similar to that just described fol-relay P except that it also includesa front contact of line 1'elayi'lV.'.-Repeater relays P and P are controlled in exactlythe same manner as repeaterrelay P y 'Relay P is provided with a'circuit which passes from transformer H through wire 39, front contact 106 of relay K wire 131, back contact 83 of track relay R wire 82, back contact 81 of stick relay K wire 80, back contactj79 of repeater relay G t, wire 78, hackcon'tact 77 of track relay R wire 132, winding of relay'P l iand wires 1'33, 134-, 60% and 55 backto transformerH Relay Pfis energized,therefore, only when relays R R G andlK are' de-energiz'ed and relay K isenergized.

Certain of the track transformers, asT

T T T, T and T have their primary windings-normally connected with a source of alternating current which connection is at times interrupted. -Refe rring particularly to transformer T this transformer is pro-' VlClBCl' with a circuit passing from transformer H ,'through wires and 135, back contact 1300f 'stickrelay K, wire 137,

primary winding 8 of track transformer T i and wires 138 and 107 back to transformer H It is evident that section DE is supp'liedwith track circuit currentby transformer T as long as relay K is de energized. The remaining track transformers are each normally disconnected from the associated section but arearranged to be attimes connected therewith. For example, track transformer T is provided with a circuit passing from transformer H through Wires 21 and 139, front contact 1 10 oi relay Pflwire 141, primary winding 8 of track transformerT and wire 24 back to transformer H It is clear that section B-C is supplied with track circuit current by transformer T only when relay P is energized; but relay P is ener gize-d only when relay K is energized and the energization of relay K disconnects energy from transformer T which normally feeds the other. end of section B C." It

therefore follows that each section is sup plied with track circuit currentv from the track transformer located atone snee the &

other of the section depending upon trafiic conditions. 7 I I The winding 15 of certain of the trick rel: ys such as R, R R R R and R isconstantly connected across the rails of the associated section. 'Referring particularly now to section 135G, track relay R has its winding constantly connected across the rails adjacent the left hand end of this section. But transformer T connected at the same point, is normally energized and to protect the relay against o er-energization, I interpose an impedance 1 1 between Winding and one rail 1 of the section BC. lVhen section B-C is supplied with track circuit current from the right hand end, however,

this impedance is not necessary, and under this condition a low resistance shunt circuit is provided around this impedance from rail 1 through Wire 142, front contact1 l8 of stick relay hi and Wire 14% back to the right hand side of winding-'15 of track relay R The remaining track relays are normally connected across the rails but are arranged to be disconnected therefrom when the track transformer located at the same end of the associated section is energized. For example,

winding 15 of relay R is providedwith a ciated line relay W and repeater relay G in the follow ng manner: Referring .part1cularly to signal S the stop, or red lamp lof this signal'is provided with a circuit which passes from the secondary of a lighting transformer J whose primary is constantly supplied with alternating current 7 from transformer H through wire 245, back con tact 24h; of relayG wire 247, lamp 1- of signal. S", and wire 248 back to transformer 5 de-energized so that lamp 4 is normally energized and signal S therefore normally displays a stop indication. The caution circuit for signal S passes from transformer J through wire 24:5, front contact 246 of relay G wire 1&9, reverse contact 150 of relay Vi Wire 152, caution lamp 5 of signal S and wire 2418 back to transformer J. I This circuit is closed only when relay G is energized and relay llv is energized by current of reverse relatiye polarity in which case lamp 5 is lighted and signal 8' displays a caution indication. The proceed circuit for this signal p sses from transformer J" through wire 2%, front contact 246 of relay G wire 149, normal. contact 150 of relay V wire 151, proceed lamp 6 of signal S and wire 248 back to transformer 3 This circuit is closed only when relay G is energized and re y W en g zed by cereal This circuit is closed whenrelay G is trol isefiected by means of s'e'lectiirs located at intervals citing the trackway, each' of which is designated by the reference char v acter X with an exponent corresponding to 89 the location." 'As here shown, one such selector is located at each end of each passing siding, but this particular location and. arrangement of selectors may be d to suit the conditions met With in each installation. These selectors are controlled in any suitable manner from the despatchers oflice through the mediumof a pair of line wires 152 and 159,. Each selector in the form here shown comprises two contacts 153- 15 l and 153-155, both of which are normally open. For purposes of the presei'it invention it is sufficient tostate thatany contact in any selector can be closed for a short interval of time by the manipulation ofthe proper controlling apparatus in the dos. patcheNs-ollice. Oneform of apparatus, which will function in this manner is illustrated and described in United States naters Patent No 1,355,055, granted to B; (l. Lealre onOct. 5, 1920, and in Greer and Lealre Patent No. 1,118,120 referred to therein, although numerous other forms of apparatus are commercially available and may be used equally well. i

When the despatcher wishesto cause sig nal to display a proceed indication, he operates suitable apparatus in the 'despatclr ers oflice for closing contact 153-155 ofselector X which closes a circuit from t ans 110 former H through wire 39, contactf153- 155 of selector X wire 156, normal or reverse contact 157 of line relay /V depending on the direction of energization of that re-, lay, wire 158, winding of relay 1 and wires 159, 54:, and 55, back totransformer H This circuit is closed only when relay N energized and contact 153- l of selector X is closed, under which conditions relay 1 is energized and is therefore. caused to close its front contacts. After a predeter' minedishort interval of time, contact'153- 55' of'sele'ctor X again opens but relay 1 is not tie-energized, its retaining circuitno v being closed which circuit passes from trans 5 former H through "wire'sj39 and 160, lea-cl; contact 161 of relay L wire162, front con tact 163 of relay I wire 16 1, winding of relay I and Wires 159, 54 and 55 back to m transformer 'By operating selector,

in this manner the despatcher energizes relay I which closes the circuit for relay G"- over its front contact and therefore causes signal S to display a proceed indication it sections E'Q, D E and Cl areunoccupied by a train moving toward theIl.eft,and

and D--E are URIOCCtlPlQClflIlCl sections 1-4 is" a caution indication if sections -Q,

occupied by a trair 1novingto'7'ard the left; If atram moving towardine rigl'it occupies any portion of the track to t'lie left of point- Q,'signal S will continue to displaya stop indication since relay i will not pick up, its circuits being broken at contact ot relay W If the (lespatcher wishes to return the signal S to stop and the apparatus associated therewith to its normal condition, he may do int rval of time contact 153 15l-. of selector X opens,thus returning the apparatus to its normal condition. Signals S and S are controlled by the associated selectorsX and X" respectively exactly as signal S is controlled by its associated selector X Means are also provided'for each section for supplying to the rails in parallel cur rent which I shall hereafter term a local current. This current is supplied by means of double secondary local transformers Jeach designated by the reference character N with an exponentcorresponding to the location. F or this purpose I connect an impedance 10 across the rails adjacent the left hand end each section, asimilar impedance 18 adjacent the right hand endof each section, and two similar impedances 11 and 12 at inte mediate points in the section.

'l raiiic moving from right to left through section C-D is controlled by a iota}; cirmiit which may be traced from secmidary 18 of local. transformer N through wire 16?, front contact 168 of line relay W wire 169, back cont ct 1Z0 of stick relay K', wire 171, back contact 172 of repeater relay P, wire 1T3, impedance 13 in section C D, through both rails of the section in parallel to impedance 10, thence through wires 17% and 175 iront' contact 176 ofrelay V and u ire 17? has.- to secondary 18 of transformer liflthe primary of which is constantly supplied With alternating current from transformer H This circuit is closedonl'y whenrelay W is energized andrelays Z and P are deenergized, underwhich condition the rails of section CD are supplied with local current of hat I, shall term F-normal relative polarityl. If, however, sectionBC is occupied] by at train ,moving' toward the left the consequei'it de-energization of line relay will close a circuit from secondary Winding 18-oflocal transformer N through wire 16.7,back contact 168 of'relay WV, wire 178, front contact '17 9 of relay K Wire 180, impedance lliin' section CD, through both rails oi'jthe section in parallel to impedance 13, thence by'wires173,-back contact 172 of relay P, .wire 171, back contact 170 of relay K", wire 169, back contact 176 of relav -W and wire 177 back to winding 1810f 'local' lransformenN This circuit isfclosed only when relays 1V K and P? are (lo-energized and relay K is energized, underwhich condition local current of what I shall term reverse relative polarity supplied to the rails of section C-D between in' pedances 11 and 13. It should be particularly pointed out that the circuit just traced is complete only when'the train occupyingsection BC is moving toward the left for if this train were moving toward the right relay K would be deeenergize'd, thus opening the" local circuit at its front contact 17 9. Traffic moving from right to left through sections B.C and JDE"and from left' ,to right through sectionsA-B is supplied withlocal current'in exactly the same manner as just described for section CD. I

Traffic moving from left/to rightthrough section .C.D is provided With local. current from secondary winding{19of-local trans former 1 D over circuitssimilar to those de: scribed above except that relay'sK wer are now energized and the circuittherefore passes over front contacts -170 2i11d172 of these I two relays, respectively, instead fof their; back contacts, ,to wire 17.1. Similar local circuits are provided for traflic moving from left to right through section BC. Similar local circuits are provided for traffic froni left to right through section D E and for traliic from right to left through "section AB,' with the single exception that'the pole-changing or reversing of the local current 1S accomplished, in these two latter cases, by means of'tlie repeater relays G located at the exit ends of th s ti i t d, Of'by means of line relays W. l

Section E Q, 1s provided with a local {circuit'which passes from winding 19 of local transformer Nf' throu h wire 181, imped ance 13 in section E,Q, through 'both rails of the section in'parallel to impedance 10,

thence by 1 wire 182, front contact; 183 of stick relay K wire 184, back contact 185 ofrelay P wire l86,'back contact 187 of relay K ,"wire .188, front contact 189 of track jrela'y R and wire 190,,back to wind I ing 19 of local transformer N L This cir-' cuit is closed only whenrelaysR and K are energized and relays Keane I are do system as a whole it should be pointed out energized, under I which conditions traflic moving from left to right through section E@ is supplied with local current of normal relative polarity. For traflic moving from right to left through section EQ the front contact 187 of relay K wire 186, front contact of section P and wire 194 back to winding 19 of local transformer N This circuit is closed only when relays R K and P are energized, under which condition therails of section E-Q are supplied with local current of normal relative polarity. It will be noticed that no means are provided for supplying a local current of reverse relative polarity to this section and that'the control of the local current is extended into the section next in advance for train movements in either direction. For example, a train occupying either section I'll-4Q, or section DE will operate to prevent the supply of local current to a train moving through section E-Q, from right to left. It will also be noticed that the local circuits extend the entire length of the section and that the intermediate impedances 11 and 12 have been omitted. r

The apparatus associated with the portion of trackto the right of point Q, is similar to the apparatus associated with the left hand end of section AB, and the apparatus located to the left of point is similarin all respects tothe apparatus associated with the left'hand end-of section E--Q,.

Before explainingv the operation of the that the trackway apparatus herein shown and described is intended for co-operation with train carried governing apparatus in the following manner: When the train is on a portion of track which is supplied with track circuit current and with local current of normal relative polarity, the governing apparatus allows the train to proceed at a high speed, as 65 miles per hour; when the train is on a portion of track supplied with track circuit current and also with local current, the relative polarity of either of which indication.

current or'currents in the track rails through train or the wheels and axles of the train will 1 shunt the track circuit current away from the receiving apparatus and the governing apparatus will then impose a low speed limitation upon the trainirrespective of trafli'c conditions. V

As shown in the drawing the parts are all in the positions corresponding to norinal conditions,,that is, the stretch of track is unoccupied and all signals display a stop 1 will now assume that the despatcher Wishes to allow a train, moving from right to left, to'passthrough the portlon of track shown in the drawing.

Relay W is energized, the circuit'for relay Vi is closed and relay W is therefore energized 1n the normal direction. Now if the despatcher closes contact 153-155 of selector K the relay 1 is energiaedand 1S maintained in th s condition until asub-i sequent energization of relay L opens the retaining circuit for relay 1 through back contact 161 of relay L. The energization of relay 1 closes the circuit for relay G which then becomes energized. v At the same time the opening of back contact 41 of relay 1 opens the circuit of relay which becomes de-energized since the branch for this circuit over a front contact of relay K is open, K being de-energizeail.v

The. de-energization of relay W' de-energizes in turn, relays VP and N Relay W is de-energized by the i openingo'f back contact of'relay G and also by the opening of back contact 196 of relay 1 The energization of relay G opens, at its back contact 246, the circuit for stop lamp t of signal S and closes at front contact 246, the -ircuitfor proceed lamp 6 of signal S2 nal S to display a proceed indication: it is, them-clear that incausing signal S to disolav a aroceed indication to allow traftie to pass from right to left, the despatcher V has caused all the opposing line relays be tween signal S and the next signal in advance, to become de-onergized.

As the train enters section Ear, acceptin; signal S track relays R and H are de-energized and sticlr'relayl K "and which becomes lighted thus causing sigrepeater relay P are energized, As a. re

suit the winding 8 of track transformer 'l. is de energizedand the shunt around impedance 1 1 of relay R is' opened Eiimultaneously, track transformer T is energized and relay R is disconnected from" the rails. Line relays;3V oandTV and slow acting relays G and'G are now doenergized'thus causing signal S to display I dication. V as the train passes through section BC made in the apparatus since relay VJ" is already tie-energized thus making it impossible topick up relay K. Track circuit current is supplied to the rails of the section-by transformer T? and localcurre'nt of normal relative polarity is supplied to the section by winding 18 of local transformer N and the train is therefore allowed to proceed throughthe section at high speed.

As the rear of the train leaves section EQ, track circuit current from trans former T energizesrelay R 'which closes its front contacts, tie-energizing relays K and P and thereby energizing track trans former T closing the shunt around imped ance l4 associated with traclrrelay R deenergizing track transformer T and reconneot-ing track relay R with the rails of the section. This relay R thereupon-becomes energized.v Relay l/V does not become energized however, because its circuit is broken at back contact 1900f relay I I Track as soon as the train enters section C D, thus energizing relay K and tie-energizing relay l Relay i l is already de-energized and relay K therefore can not pick up' As the rear of the train passes out of section D E, track relays are energized, thus completing thecircuitfor relay W But relay -W, which controls the polarity of this ciu'rent'supplied to this relaf. is de-energiaed and the relay W is therefore energized in the reverse direction.

Furthermore, relay P" is still energized and l 3' G is consequently energized thus causingsignal to display a caution'in- The operation of the apparatus will be readily understood from the fore, going andvis similar in all respects to: the operation of the apparatus associated with section D. As the train passes out of section CD, the energization'of track relays R and R de-ener 'izesrela :KFandcauses re to becomeiener 'ized, there by 11Gl9,'1Z1I1g' relay N in theynormal direction and causing signal S to display a proceed, indication.

Assumingthat signal. SFis at stop, as' shown in the drawing, the entrance of thetrain, wnich has beerrpermrtted to pass through section B O at miles-per hour int-ofsection AB causes track relays ll?"- As the relays R and R are tie-energized and R to become tie-energized, thus energizing relays K and P and transformer T This operation also disconnects track relay R from the rails of the section, deenergizes transformer T, and opens the shunt around impedance 14 associated with relay R I Track circuit current is supplied to the rails of the section by transformer T and since relay I is tie-energized, relay G- isalso tie-energized and the rails of section AB'are supplied with, local current of reverse relativepolarity between impedances 11 and 13 but not between impedances 10 and 11. I The s )(CCl ot the train is therefore reduced, bythc governing; apparatus, to 35 miles per hour as soon as it enters section J- -l.l under t-hese conditions. may then proceed at. 35 miles per hour or less, as far'as impedance ll in section A 3 beyond which it mayonly proceed at speeds below 15 miles per hour.

It thedespatcher closes contact 153155 of selector -X the apparatus located at point A will operate in the same manner as that located at point F, and signal S will display a proceed indications Under these conditions, relay G will ofcourse, beenergized, local current of normal'relative polarity will be supplied to the rails of section. A-B throughout the section and the The train train will be allowed-to proceed at high 7 speed. I

I'will now assume that a train moving from right to leftoccupies section DE. As explained before, relays R, K9, P 5 and G will be (lo-energized as a result of the presence of this train, and signal C will be at stop.f--Now if a following: train should attemptto enter the stretch of track shown in the drawing, the governing appa- 'ratus would reduceits speed to miles per hour-at the right hand end of the section to the right of Q, and would further reduce the speed of the train to 15 .m'iles per hour at impedance 11 immediately to the right of Q as explained in connection with section AB. If the. train should pass point Q, the low speed limitation would still be enforced because the local circuit is open at front Contact 192 of track relay R and front-contact 189 of relay Y which can not icku 3, due to the de-ener 'ization of rela G In addition the train would be deprived of track circuit current after passing the point ofconnection of transformer T by the shunterl'ect of its own wheels and axles, because the energization of transtormerT requires the energization of relay K which we have seen can not occur under theseconditions.

I will nowza ssume that a' train 'moving; from right to left occupies section BC.

It is plain that a following train, passing through section'DeE at high speed, will be. reduced to 35 miles per hour at po nt I by the reversal of polarity of local currentrcsulting from the de-enern'ization 0t line relay ll. Similar protection against following trains i afforded byapparatus associated with the remaining sections and will be readily understood from the foregoing.

the route is set up for trafiic troin right to left, that is, it sio'nal is at procoed, the de-cnergiaation or all the cpposi line relays lV, resulting from the acccptin of the signal by train moving in the direction in 'which the signal governs, in'iposos restricted speed limitations upon all filo moving in a di'ifectirn opposite to the route set up.

As rning tiat tratlic from right to l rt, X track shown in. the drawin and that the dcspatcher wishc n1 occi l pied train movements from lGlo to right throne: i

the portion of track to the right oi i i S, he momentarily closes :outact 153 '3 of selector thereby closing; the circuit for relay L which becomes energized. The opening;' of back contact l ll of relay L deenergizes relay I and'thereby ole-energizing relay G This changes the indications of signal S from proceed to stop, The closing ot back contact ct relay l and 1 186 of relay 1 the closur of back contact allows relay "W to picl: up and the cl 1s 01" back contact ell of relay 1 c oses the branch for relay VJ". Now it the despatcher closes contact of selector X the route will be set up for from left to right in a manner entirely analogous to t described in explaining the operation of the apparatus for movements from left to right. It is of course understood that the apparatus to the left of point E is responsive to manip ulations of a selector not shown in the drawing in eiiactly'the same manner that the apparatus to the right 'ot selector X is responsive to manipulations of that selector.

In the light off the preceding description, clear that the despatchcr controls not only the indication displayed by the signals but also the local circui s for the portions'ot track governed by those ials. For e an'iple, with the appara us in the pos ion shown in the drawing nal S disola s stop indication and a ain attempting to pass this signal is immediately nought to a low s nmd by the interruption ot the local current since one local circuit for section l Q, is broken at front contact 18? of relay K which can not pick up because of the-deenergized condition of relay G and the o'her local circuit tor this section is brokeir at front contact 183 of relay K. has been pointed out. hereinbe'tore this low speed limitation is imposed upon the train throughout the stretch of track shown in the drawing. If, however, the'oespatcher car es relay I to become energized, thus energizscribed only one form and arrangement of railway traffic controlling apparatus embodying my invention, it is understood that various changes and modificationsmaybe made therein within the scope of the appended claims without departing from the spirit and scope of my invention. f

Having thus described. my inve I claim is: i e

I 1. In combination, a; stretch of railway trace, a selector comprising two' contacts and controlled from a distant point, an clectro-responsive device for controlling traiiic through said stretch, a circuit for said device including one of said contacts, a second electro-responsive device controlled by said second contact, a third contact con trolled by said second device and an auxiliary ntion, what sic circuit for said first device including said third contact.

2. In combination, a stretch of railway track, a relay for governing t-ra'iiic through said stretch, a selector controlled from a dis tant point and comprising two contacts, a pick-up circuit for said relay controlled by the first contact on said selector, an auxiliary relay control ed by the second contact on said selector, and a retaining circuit for said first relay including a front contact thereon and a back contact on said auxiliary relay.

l. In combination, a stretch of railway track, a relay responsive to traffic conditions in said stretch, an electro-responsive device,

means controlled by said relay and operated 'lroin a distant point tormovlng said device to an operative position, means for retaining said device in its operative position, traiiic governing apparatus controlled by said device, and means operated from a distant point torrendering said retaining means inefi'ective.

5. In combination, a stretch of railway track, a'device for governing trailic over said stretclna relay for controlhng said device, a

iio

second relay for controlling said first irelay,

two normally open contacts, meanscontrolled from a dlstant point formomentarily closing one contact orthe other at will, and pick-up ing means for subsequently maintaining two contacts, respectively. I 1

6. In C0mb1Ila-t101n fi, stretch of ra lway traclna device for governing'trafiic over said circuits for said two relays-including. said stretch, a relay for controllingisaid device,

a second relay for controlling saidffirst'relay,

two normally openvcon tacts, means controlled track, two normally open contacts, means operated from a distant point for momentarily closing either of said contacts at will, means controlled by one of said contacts for supplying a train governing current to said stretch, retaining means for continuing such supply after the opening of said contact, and

means controlled by said second contact for rendering said retaining means ineffective.

8. In combination, a stretch of railway track, a source of train governing current, two normally open contacts, means operated from a distant point for momentarily closing either of said contacts, means controlled by one of said contactsfor connecting said source with the rails of, the section, and means controlled by the other said contact for interrupting said connection. c v

9. In combination, a stretch of railway track, a source of train controlling current, two normally open contacts, means operated from a distant point for momentarily closing either of said contacts, means controlled by one of said contacts for connecting said source with the rails of the section, retainsaid connection after the said contact has re-opened, and means controlled .by the remaming said contact for rendering such retaining means ineffective.

10. In combinat1on,a stretch of railway to the rails of said section.

track, a source of train controlling current, two normally open contacts, means operated from a distant point for momentarily closing either of said contacts, means controlled by one of said contacts for connecting said source with the rails of the section, retain ing means responsive to traflic conditions in said section for subsequently maintaining said connection after the said contact'has reopened, and means controlled by the remaining said contact for rendering such retaining 1 means inefl'ective. v v

11. In combination, a sectlon' of railway track, a source of train controlling current,

a repeater relay, means c'ontrolled by said repeater relay and respons ve to traffic conditlons in said section for connecting said source with the rails in parallel of such section, a second relay for operating saidrepeater relay, selecting means controlled from a distant point forenergizing said secondprelay, means for subsequently continuing' said energization, and separate means controlled by saidselecting means for dez-energizmgsaid secondrelay; I

12. In comb 1nat1on,a forward and arear section of railway track, a source of train controlling current, a repeater relay, a'tracl; relay for said forward section, means controlled ,by said repeater relay and said track relay for connecting said source with thev rails in parallel of said rear sect-ion, and

selecting means operated from a distant point for controlling said repeater relay.

13. In combination, a section of railway track, two normally open contacts, means operated from a distant point for momentarily closing either of said contacts at will, a relay, a pick-up circuit for said relay including one of said contacts, a second relay, a retaining circuit for said first relay including a contact on said second rela ,and a train controlling circuit for sai section controlled by said first relay.

14:. In combinatioma portion of railway track, normally ineflective means for supplying train governing current to the rails of said portion, a selector located adjacent said portion of track and controlled from ,a distant point, and apparatus controlled by said selector and by traflic conditions in ad-- Vance of said portion of track for rendering said means effective to supply train governing current to the rails of said section.

115/In combination, a portion of railway track, normally inefiective means for supplying train governing current] to the rails of, said portion, a selector located adjacent said portion of track and controlled from a distant point, a track relay associated with 'a section in advance of said portion of track,

and apparatus controlled by said selector and by said track relay for rendering said means 1 effective to supply train governing current 16. In combination, a section of railway track, a relay, apparatus controlled by said 'tion and controlled from a distant'point,

and means for controlling said relay by said selector. Y

"17. In combination, a section of railway track, a relay, apparatus controlled by said f relay for supplying alternating, train govsection, a selector locatedadjacent said section and controlled from a distant, point, and means for controlling said relay b said 10 selector and by traffic conditions in a Vance of said section. c

In testimony whereof l afiix my signature.-

- RONALD A. MOOANN. 

